Glass/plastic compounds

ABSTRACT

The invention relates to glass/plastic compounds based on thermoplastics, containing low-melting sulphophosphate glass with the following composition: between 4 and 10% Li 2 O, between 4 and 10% Na 2 O, between 4 and 8% K 2 O, between 1 and 2% CaO, between 35 and 37% ZnO, between 0 and 3% La 2 O 3 , between 19 and 22% P 2 O 5  and between 19 and 22% SO 3 , in addition to a high-performance thermoplastic.

[0001] The invention relates to glass/plastic compounds based onthermoplastics, and also to a process for their preparation.

[0002] In electrical engineering and electronics, reinforced plasticsmaterials, especially based on thermoplastics, are used for producingdevices or components. The reinforced thermoplastics usually used hereare thermoplastic compounds comprising glass fiber. However,—inparticular at high filler levels—these materials have disadvantageousprocessing performance due to poor flowability and high tooling wear.The mechanical properties are moreover frequently anisotropic—due toorientation of the glass fibers during processing. In the case of movingparts produced from materials of this type, operation results insignificant formation of crumb, and this impairs function particularlyin the case of devices used in electrical engineering. In addition, ifthe material of glass-fiber-reinforced thermoplastics is recycled, theglass fibers degrade. The consequence of this is significant impairmentof mechanical properties of compounds prepared using these glass fibers.

[0003] EP 0 365 236 A1 discloses an alloy in the form of a melt mixturemade from at least one inorganic glass and/or one glass ceramic, andfrom at least one organic thermoplastic or thermoset polymer. The glassor glass ceramic content here is from 30 to 90% by volume. The glasscomponent is a phosphate glass, for example one with the followingcomposition (in mol %): from 44 to 58% of P₂O₅, from 4 to 10% ofAl₂O₃+B₂O₃ (with from 0 to 7% of Al₂O₃ and from 0 to 10% of B₂O₃), from10 to 45% of Li₂O+Na₂O (with from 0 to 30% of Li₂O and from 10 to 30% ofNa₂O), from 0 to 20% of Cu₂O and from 10 to 30% of Li₂O+Cu₂O. Thethermoplastic polymer is one selected from the following group: polyarylether ketones, polyphenylene sulfides, polyfluorinated resins,polyetherimides, liquid-crystalline polyesters, polyether sulfones,polytetrafluoroethylenes, polyether ether ketones, polyether ketones,polyethyl terephthalates, polybutyl terephthalates, melamines andpolycarbonates. The thermoset polymer may be an epoxy resin, a siliconeresin, a polyimide, a phenolformaldehyde resin, or a diallyl phthalate.

[0004] To improve the moisture resistance of alloys of theabovementioned type—and corresponding composites—it is known that,besides the matrix material made from thermoplastic or thermoset polymerand the phosphate glass, use may be made of a water-soluble stabilizercomponent which is a source of metal cations of valency 2+ or higher(see EP 0 587 082 A1 and EP 0 587 083 A1). Metal cations of this typeare Ba²⁺, Mg²⁺, Ca²⁺, Al³⁺, Zn²⁺, Sr²⁺, and Fe³⁺. However, thestabilizer component, which is a metal oxide or another metal compound,markedly impairs processing performance at high filler content, i.e.high glass content, by causing a considerable rise in viscosity.

[0005] Other known glasses for glass/plastic blends are those with lowglass transition temperature, based on alkali metal zinc pyrophosphatesand on alkali metal zinc sulfophosphates (see: G. H. Beall in“Proceedings of XVII International Congress on Glass”, Peking, China,Oct. 9-14, 1995, pages 174-183). Examples of the composition of theglasses are as follows (in mol %):

[0006] pyrophosphate glasses: from 30-40% of P₂O₅, from 20 to 55% ofZnO, from 0-4% of Al₂O₃ and from 10-30% of R₂O, i.e. from 3-12% of Li₂O,from 4-18% of Na₂O₃, from 0-12% of K₂O, and from 0-17% of Cu₂O;

[0007] sulfophosphate glasses: from 21-33% of P₂O₅, from 9-17% of SO₃,from 35-51% of ZnO, and from 10-20% of R₂O, where R₂O is mixed alkali.

[0008] These glasses are used together with the following thermoplasticpolymers: polyether ketones, aromatic liquid-crystalline polyesters,polyaryl sulfones, perfluoroalkoxy resins, and polyetherimides.

[0009] Glass/plastic compounds, in particular those based onthermoplastics and used to produce glass-reinforced plastics parts orglass-reinforced plastics structures, are intended to have a specificproperty profile. The following applies to the properties of thematerial or the properties of the plastics parts:

[0010] homogeneous filler distribution

[0011] dimensional stability

[0012] solder bath resistance (SMD capability)

[0013] miniaturizability of the glass structures extending to the μrange

[0014] good chemicals resistance, i.e. resistance to water, acids andbases

[0015] intrinsic flame retardancy

[0016] good tracking resistance

[0017] high capability for recycling or reprocessing.

[0018] The following processing requirements have to be complied with:

[0019] minimum processing temperature (however, processing temperatureis inevitably above 260° C. due to the requirement for solder bathresistance)

[0020] viscosity of the components plastic, i.e. thermoplastic, andglass, selected to be appropriate to one another (under processingconditions)

[0021] good flowability at high filler levels

[0022] possibility of controlling the glass structures (isotropic oranisotropic)

[0023] low tooling wear (due to advantageous abrasive properties).

[0024] Another criterion is a low level of crumb formation duringoperation, i.e. low abrasion, in particular in the case of moving parts.In addition, to permit recycling of material, a demand is that recyclingdoes not damage the reinforcing material, i.e. the glass component.Furthermore, it is intended that the glass/plastic compounds be capableof production with maximum cost-effectiveness and minimum cost.

[0025] When glasses are used in electrical engineering or electronics,good moisture resistance is of decisive importance. However, knownglasses with low glass transition temperature, i.e. from about 220 to230° C. are susceptible to hydrolysis and in certain instanceswater-soluble. Although addition of copper oxide (Cu₂O) is claimed inprinciple to permit production of glasses with greater hydrolysisresistance and a glass transition temperature of from about 230 to 250°C., glasses of this type are still markedly more susceptible tohydrolysis than glasses with high glass transition temperature (see: G.H. Beall, loc. cit.); in addition, industrial production is excessivelycomplicated and excessively expensive. On the other hand, glasses withglass transition temperature T_(g)>300° C. cannot be used for the statedpurpose. The reason is that the glasses are insufficiently flowableuntil the temperature is above the glass transition temperature by from70 to 80° C., and therefore processing with a thermoplastic becomespossible only at temperatures above 370-380° C.

[0026] It is an object of the invention to provide glass/plasticcompounds based on thermoplastics, which to a very substantial extentmeet the requirements placed on the properties of compounds of thistype, and also the demands with regard to processing, operation, andrecycling of material. The glass here is in particular intended to haverelatively high flowability and hydrolysis resistance, and it is alsointended that fine distribution of the glass (<10 μm) be possible at anydesired concentration.

[0027] According to the invention, this is achieved by way ofglass/plastic compounds which comprise the following components:

[0028] a sulfophosphate glass with a low melting point and having thefollowing composition: from 4 to 10% of Li₂O, from 4 to 10% of Na₂O,from 4 to 8% of K₂O, from 1 to 2% of CaO, from 35 to 37% of ZnO, from 0to 3% of La₂O₃, from 19 to 22% of P₂O₅, and from 19 to 22% of SO₃, and

[0029] a high-performance thermoplastic.

[0030] A “low-melting” sulfophosphate glass is a glass with low glasstransition temperature T_(g), in particular a glass with T_(g)<about500° C. A “high-performance thermoplastic” is a high-performancepolymer, and specifically in the present case a heat-resistant polymeror high-temperature-resistant polymer. This is important because thetemperature during preparation of the compounds is >300° C., as is theprocessing temperature (for the compounds).

[0031] The glass/plastic compounds of the invention or glass/polymercompounds of the invention have good mechanical and thermal properties,and also good processing properties, in particular good flowability,even at high filler content, i.e. high glass content. They also haveexcellent chemical resistance, in particular to water, acids, and bases,and indeed, surprisingly, without addition of stabilizers. Theglass/plastic compounds moreover have excellent abrasion resistance, andrecycling of the material is possible without difficulty because thereis none of the shortening of the glass component which occurs withglass-fiber-reinforced compounds. In comparison with known compounds orknown blends (see: G. H. Beall, loc. cit.), an advantage is that neitherSrO nor Al₂O₃ is present in the glass component. Specifically, strontiumis relatively expensive, and the dissolution of aluminum oxide in theglass on an industrial scale is excessively complicated. In contrast,the compounds of the invention are capable of meeting industrialrequirements and can be produced on the ton scale.

[0032] The sulfophosphate glasses present in the glass/plastic compoundsof the invention have a glass transition temperature of 250≦T_(g)≦280°C. The composition of the sulfophosphate glass preferably found in thecompounds (in mol %) is: 4.9% of Li₂O, 9.4% of Na₂O, 7.1% of K₂O, 1.6%of CaO, 36.6% of ZnO, 20.0% of P₂O₅, and 20.4% of SO₃. A glass of thistype has a glass transition temperature of 268° C. An example of anothercomposition of a glass is as follows (in mol %): 9% of Li₂O, 5% of Na₂O,7% of K₂O, 1.6% of CaO, 37% of ZnO, 20.4% of P₂O₅, and 20% of SO₃(T_(g)=280° C.). An example of a further composition of a glass is asfollows (in mol %): 4.8% of Li₂O, 9.2% of Na₂O, 6.9% of K₂O, 1.6% ofCaO, 35.9% of ZnO, 2.0% of La₂O₃, 19.6% of P₂O₅, and 20.0% of SO₃(T_(g)=275° C.)

[0033] The high-performance thermoplastic used is advantageously apolyether ether ketone (PEEK), a polyetherimide (PEI), a polyphenylenesulfide (PPS), a partly aromatic polyamide, such as polyphthalamide(PPA), or a liquid-crystalline polymer (LCP). For these polymers, theglass transition temperature of the glass component is compatible withthe processing temperature of the thermoplastic material. Otherhigh-performance thermoplastics which may be used as polyaryl etherketones (PAEK) in general, for example polyether ketones (PEK), and alsopolysulfones (PSU), in particular polyether sulfones (PES), andpolyphenylene sulfones (PPSU).

[0034] The glass component content, i.e. sulfophosphate glass, in theglass/plastic compounds is preferably from 15 to 60% by weight. Forparticular applications, however, the glass content may be up to 80% byweight. The compounds may also comprise conventional additives, such ascolor pigments and stabilizers. Examples of possible applications are insensors, actuators, plug connectors, electro-optical components, andrelays.

[0035] The preparation of the glass/plastic compounds according to theinvention begins by preparing a masterbatch with glass content of from60 to 90% by weight from the two components, i.e. sulfophosphate glassand high-performance thermoplastic—at an elevated temperature.

[0036] Surprisingly, it has been found here that the use of glassparticles (glass grains) with diameter ≦1.5 mm gives glass structures inthe μm and sub-μm range uniformly distributed in the masterbatch.

[0037] The further processing then uses addition of furtherhigh-performance thermoplastic to the masterbatch—at elevatedtemperature—to reduce glass content to 15-60% by weight. This has noeffect on the structure and the homogeneous distribution of the glassparticles, i.e. they are retained. Surprisingly, control experimentsshowed that if a batched material by way of example with glass contentof 15% is used directly as starting material, the size of the structuresand their distribution are not of the type described. Rather, uniformlydistributed glass structures, extending as far as the nm range, can onlybe produced starting from a masterbatch with high content of thespecific sulfophosphate glass in a high-performance thermoplastic.

[0038] The glass/plastic compounds of the invention are prepared atelevated temperature, preferably at from about 320 to 420° C. Whenpreparing the compounds it is also possible to adjust the structure ofthe glass particles (isotropic/anisotropic) by way of the processingconditions. The compounds also have good coupling of the glasscomponents to the thermoplastic material, as shown in particular by thegood chemicals resistance.

[0039] One of the ways in which the good coupling of the glass componentis achieved is that the glass comes into contact with the thermoplasticmaterial in a molten state, and therefore at the juncture of contact hasfree and active polar end groups on its surface which have not yet beendeactivated by hydroxy groups, for example from the water present inair. These reactive end groups interact with the surface of thethermoplastics with which they come into contact, thus bringing aboutparticularly stable coupling of the two materials, glass andthermoplastic, to one another.

[0040] Since it is possible to start from relatively coarse particles ofa sulfophosphate glass, the particle size being ≦4 mm, preferably ≦1.5mm, the process of the invention therefore provides the opportunity oflow-cost production of glass/plastic compounds in which the glassparticles have been uniformly and homogeneously distributed in ahigh-performance thermoplastic, and moreover are capable of adjustmentas desired by extending into the nm range. This is achieved by way ofthe viscosity of the individual components, and by way of the processconditions, in particular the processing temperature; the viscosityratio of plastic to glass is generally about 1:1000. Compounds of thistype are particularly suitable for producing devices or components forelectrical engineering or electronics. Specifically, the substantialrequirements in relation to properties of the material and processingproperties are fulfilled here, and reliable operation is ensured. Thecompounds also permit a marked reduction in the variety of materialsused in devices and components in electrical engineering andelectronics, in particular with respect to plastics, extending as far asuse of just one type. This permits low-cost recycling of material, andspecifically with retention of the properties of the filler.

[0041] Nowadays, components and component parts for the various unitsuse different thermoplastics with a variety of fillers and reinforcingmaterials, and moreover in different proportions. This may beillustrated in more detail taking the example of what is known as a“slim-line mains relay” (SMR).

[0042] In a relay of this type, the actuator is composed of aliquid-crystalline polymer (LCP) with 30% of glass fiber reinforcement,and the base is composed of a polyphthalamide (PPA) with 25% by weightof glass fiber reinforcement and 25% by weight of mineral reinforcement,and the coil former likewise is composed of polyphthalamide, but with45% by weight of glass fiber reinforcement, and the cap is composed of apolybutylene terephthalate (PBT) with 15% by weight of glass fiberreinforcement. In addition to this, the polyphthalamide for the base andthe coil former comprises a halogen-containing flame retardant.

[0043] Examples of comparable diversity of materials are also found insensors, actuators, semiconductor components, and plug connectors. Thesmallness of the units, together with the diversity of types ofmaterials used and the halogen-based flame retardancy make it almostimpossible to recycle components or component parts, and this is alsovery costly. As stated above, marked shortening of the glass fibers alsooccurs when glass-fiber-reinforced materials are reclaimed orreprocessed. This has a marked adverse effect on the mechanical andthermal properties of the reused material.

[0044] Use of the glass/plastic compounds of the invention, whichcomprise a low-melting sulfophosphate glass and a high-performancethermoplastic, can solve the problems mentioned. The high-performancethermoplastic here is in particular polyphenylene sulfide (PPS),polyether ether ketone (PEEK), polyetherimide (PEI), polysulfone (PSU),polyether sulfone (PES), or partly aromatic polyamide, such aspolyphthalamide (PPA). The glass component is selected to be appropriatefor the respective plastic, and has a glass transition temperature inthe range from 250 to 280° C. The glass component is flowable at theprocessing temperature of the compounds, which is from about 320 to 420°C. The content of the glass component in the compound is from 15 to 80%by weight, preferably from 15 to 60% by weight.

[0045] Since the glass component is flowable at the processingtemperature, the compounds exhibit very good flow behavior—despite thehigh glass content, and it is possible to produce components withcomplicated geometry and thin walls. It is also possible to producedesired fiber-shaped or bead-shaped glass structures in the component byway of appropriate selection of the viscosity of thermoplastic andglass, and by way of suitable component design. With this, there is thepossibility of providing fiber reinforcement in mechanically stressedzones of a component, while at the same time in zones which have to meethigh dimensional stability requirements producing a bead structure whichensures that the material behaves isotropically.

[0046] In the case of a slim-line mains relay, all four of theindividual components may be manufactured from the same underlyingthermoplastic, for example polyphenylene sulfide, with different glasscontents which comply with the requirements with respect to mechanical,thermal, and electrical processing properties. It is also significantthat these components are flame-retardant without any use of halogens.

[0047] Since the glass fibers or glass beads produced during processingare newly melted during any reprocessing, and are therefore regenerated,fibers—unlike conventional glass fibers—cannot become shortened. Thereused material therefore has the same mechanical and thermal propertiesas virgin product. The entire plastics content of the network relay canbe reclaimed and recycled simply and at low cost. The recycled materialobtained is a compound whose glass content is composed of the glasscontents of the individual components. During reclamation it is theneasily possible to meter in plastics raw material or low-melting glassin order to set a desired glass content in the recycled material.

[0048] The glass/plastic compounds of the invention therefore haveexcellent suitability for halogen-free flame-retardant components andcomponent parts for electrical engineering and electronics, where thesecomprise a single type of material and provide high recyclability. Theunits here use the same underlying thermoplastic for all of theindividual component parts, and these can be mixed with various contentsof a low-melting glass. The component built up from individual componentparts of this type can be recycled simply and at low cost.

[0049] The invention will now be further illustrated using examples. Thesulfophosphate glass used here has the following composition (in mol %):4.9% of Li₂O, 9.4% of Na₂O, 7.1% of K₂O, 1.6% of CaO, 36.6% of ZnO,20.0% of P₂O₅, and 20.4% of SO₃.

EXAMPLE 1

[0050] Preparation of a Masterbatch

[0051] The masterbatch is preferably prepared in a corotating orcounter-rotating twin-screw extruder with 11 separate barrel heatingzones (barrel zone 1: feed hopper; barrel zone 11: die). The design ofthe screws is such that there are two or more kneading blocks andshearing blocks, and also melt flow restrictors, incorporated intobarrel heating zones 3-5. Zones 6-9 have dispersing elements, and zones10 and 11 comprise conveying elements.

[0052] The plastics used are either in powder form or in pellet form(lenticular pellets or cylindrical pellets of length from 3 to 4 mm anddiameter from 2 to 5 mm); the grain size of the glass is ≦1.5 mm. When apulverulent plastic is used, a dry mix (premix) is first made ready withthe corresponding ratio of glass (from 60 to 90%) to plastic from 40 to10%), and this is then metered into the main feed (feed hopper) of theextruder. When plastics pellets are used, the two components are meteredinto the feed hopper by way of metering systems as required by theircontent. This procedure may also be used when pulverulent plastics areused. It is also possible to meter the pulverulent plastic or plasticspellets into the feed hopper of the extruder and to meter the glass byway of ancillary metering in barrel zones 3-5. Prior to processing, boththe glass and the plastic or, as appropriate, the dry mix are thoroughlypredried for at least 4 h at from 100 to 150° C. The compound isdischarged through a pelletizing die, and is cooled in an attachedwaterbath, and then comminuted in a pelletizer. For very high glasscontents it is advisable to use a die-face cutter.

[0053] (a) Preparation of a masterbatch based on PPS powder; glasscontent: 70% by weight Barrel temperature profile: Barrel zones: 1 2 3-56-9 10 11 100 300 335 330 330 330° C. Screw rotation rate: 65 rpm

[0054]  With this type of temperature profile, a melt temperature ofabout 345° C. is measured at the die (barrel zone 11). The size of theglass particles in the masterbatch is less than or equal to 10 μm, andthey have homogeneous distribution.

[0055] (b) Preparation of a masterbatch based on PEEK powder; glasscontent: 65% by weight Barrel temperature profile: Barrel zones: 1 2 3-56-9 10 11 100 350 375 370 370 370° C. Screw rotation rate: 60 rpm

[0056]  With this type of temperature profile, a melt temperature ofabout 395° C. is measured at the die (barrel zone 11).

[0057]  The size of the glass particles in the masterbatch is less thanor equal to 5 μm, and they have homogeneous distribution.

[0058] (c) Preparation of a masterbatch based on PEI pellets; glasscontent: 60% by weight Barrel temperature profile: Barrel zones: 1 2 3-56-9 10 11 100 350 385 375 375 375° C. Screw rotation rate: 60 rpm

[0059]  With this type of temperature profile, the melt temperaturemeasured at the die (barrel zone 11) is about 400° C. The size of theglass particles in the masterbatch is less than or equal to 1 μm andthey have homogeneous distribution.

EXAMPLE 2

[0060] Reduction of Glass Content in Masterbatch of Example 1

[0061] The glass content in the masterbatch is reduced in the twin-screwextruder described (see example 1). The final glass content of from 15to 60% by weight may be set in two ways:

[0062] (i) Masterbatch pellets and base material are weighed out asrequired by their proportions, corresponding to the final glass contentto be set, and made ready in a dry mix. This dry mix is metered into thefeed hopper of the extruder. The final compound is therefore prepared ina second extruder pass.

[0063] (ii) Preparation takes place together with masterbatchpreparation in the same extruder pass, by using a second ancillarymetering unit to meter base material—as required by the glass content tobe set—in barrel zones 6-9.

[0064]  Only one extruder pass is therefore required to prepare thefinal compound.

[0065] Version (ii) is preferred here, since the materials are onlyexposed once to the thermal stress in the preparation process, andexcessive molecular degradation of the base material is thereforeavoided.

[0066] In version (i), the barrel temperature profile in zones 3 to 11is in each case below the corresponding temperature profile of example 1by approximately from 15 to 20° C.

[0067] (a) Reduction of glass content in masterbatch based on PPS powderwith glass content of 70% by weight for preparing a compound with 25% byweight glass content using version (i) Barrel temperature profile:Barrel zones: 1 2 3-5 6-9 10 11 100 300 320 315 315 315° C. Screwrotation rate: 63 rpm

[0068]  With this type of temperature profile, a melt temperature ofabout 330° C. is measured at the die (barrel zone 11). The size of theglass particles in the compounded material is less than or equal to 10μm and they have homogeneous distribution.

[0069] (b) Reduction of glass content in masterbatch based on PEEKpowder with glass content of 65% by weight for preparing a compound with40% by weight glass content using version (ii) Barrel temperatureprofile: Barrel zones: 1 2 3-5 6-9 10 11 100 350 375 370 370 370° C.Screw rotation rate: 60 rpm

[0070]  With this type of temperature profile, a melt temperature ofabout 390° C. is measured at the die (barrel zone 11). The size of theglass particles in the compounded material is less than or equal to ≦5μm and they have homogeneous distribution.

EXAMPLE 3

[0071] Chemicals Resistance

[0072] (a) Hydrolysis resistance

[0073]  To test the hydrolysis resistance of the pure glass, the glassis stored for 21 days at room temperature in distilled water, and thenthe pH is determined using litmus paper. Result: pH=7, i.e. neutralbehavior.

[0074]  The same specimen of glass is then stored for 5 days at 80° C.in distilled water, and the pH is determined by means of litmus paper.Result: pH=7, i.e. neutral behavior.

[0075] (b) Chemicals resistance of a compound based on PEEK powder withglass content of 40% by weight

[0076]  Test specimens made from this compound are stored in distilledwater, 1% strength HCl, and 1% strength NaOH at room temperature, andthe increase or decrease in weight is then measured after variousstorage times, and the percentage increase or decrease in weight iscalculated. The corresponding specimen weight prior to start of storageis used as reference value. The specimens are predried for 4 h at 150°C. before the measurement and storage process begins. Medium Material 24h 100 h 400 g 1000 h H₂O dist. PEEK  0.09%  0.14%  0.26%  0.34% PEEK +40% glass  0.03%  0.12%  0.34%  0.56% 1% HCl PEEK  0.08%  0.13%  0.23% 0.32% PEEK + 40% glass −0.23% −0.28% −0.21% −0.01% 1% NaOH PEEK  0.09% 0.14%  0.25%  0.33% PEEK + 40% glass −0.16% −0.16% −0.03%  0.14%

[0077] (c) Chemicals resistance of a compound based on PPS powder withglass content of 40% by weight

[0078]  Test specimens made from this compound are stored in distilledwater, 1% strength HCl, and 1% strength NaOH at room temperature, andthe increase or decrease in weight is then measured after variousstorage times, and the percentage increase or decrease in weight iscalculated. The corresponding specimen weight prior to start of storageis used as reference value. The specimens are predried for 4 h at 150°C. before the measurement and storage process begins. Medium Material 24h 120 h 456 h 648 h H₂O dist. PPS  0.005% 0.014%  0.03% 0.035% PPS + 40%glass  0.037% 0.063%  0.16%  0.21% 1% HCl PPS  0.009% 0.014% 0.028%0.030% PPS + 40% glass  −0.13% −0.10% −0.02% 0.007% 1% NaOH PPS  0.005%0.014% 0.030% 0.033% PPS + 40% glass −0.075% −0.05% 0.025% 0.075%

EXAMPLE 4

[0079] Friction and Wear

[0080] Frictional performance and wear performance is tested in apin/disk arrangement. Experimental parameters; Friction disk SteelSurface roughness of friction disk 0.8 μm Pressure 4 N/mm² Frictionalvelocity 0.5 m/s Temperature 23° C.

[0081] Wear (in μm) and coefficient of friction are determined oninjection-molded test specimens (area 10 mm×4 mm) which had been takenfrom a dumbbell specimen. The duration of the experiment was 15 h afterexpiry of the start-up phase. Comparison is made between a compoundbased on PPS with 40% by weight glass content and a correspondingcompound with glass content of 60% by weight, and a commerciallyavailable PPS with 40% by weight of glass fibers (PPS Gf 40). Wear in 15h Coefficient of Material μm friction PPS Gf 40 950 0.32 PPS + 40% glass140 0.32 PPS + 60% glass  20 0.30

What is claimed is:
 1. A glass/plastic compound based on thermoplastics,at least encompassing a sulfophosphate glass with a low melting pointand having the following composition: from 4 to 10% of Li₂O, from 4 to10% of Na₂O, from 4 to 8% of K₂O, from 1 to 2% of CaO, from 35 to 37% ofZnO, from 0 to 3% of La₂O₃, from 19 to 22% of P₂O₅, and from 19 to 22%of SO₃, and also encompassing a high-performance thermoplastic.
 2. Theglass/plastic compound as claimed in claim 1, characterized in that itcomprises a sulfophosphate glass of the following composition: 4.9% ofLi₂O, 9.4% of Na₂O, 7.1% of K₂O, 1.6% of CaO, 36.6% of ZnO, 20.0% ofP₂O₅, and 20.4% of SO₃.
 3. The glass/plastic compound as claimed inclaim 1 or 2, characterized in that the high-performance thermoplasticis a polyether ether ketone, a polyetherimide, a polyphenylene sulfide,a partly aromatic polyamide, or a liquid-crystalline polymer.
 4. Theglass/plastic compound as claimed in any of claims 1 to 3, characterizedin that the sulfophosphate glass content is from 15 to 60% by weight. 5.A process for producing glass/plastic compounds as claimed in one ormore of claims 1 to 5, characterized in that, in a first step, amasterbatch with glass content of from 60 to 90% by weight is preparedfrom a sulfophosphate glass and a high-performance thermoplastic atelevated temperature, and that, in a second step, the glass content isreduced to 15-60% by weight by adding further high-performancethermoplastic at elevated temperature.
 6. The process as claimed inclaim 5, characterized in that the temperature is from 320 to 420° C. 7.The process as claimed in claim 5 or 6, characterized in that use ismade of glass particles with a diameter of ≦1.5 mm.
 8. The use of theglass/plastic compounds as claimed in one or more of claims 1 to 4 incomponents or component parts for units.
 9. An electrical and/orelectronic component which encompasses a glass/plastic compound with alow-melting sulfophosphate glass of the following composition: from 4 to10% of Li₂O, from 4 to 10% of Na₂O, from 4 to 8% of K₂O, from 1 to 2% ofCaO, from 35 to 37% of ZnO, from 0 to 3% of La₂O₃, from 19 to 22% ofP₂O₅, and from 19 to 22% of SO₃, and also encompassing ahigh-performance thermoplastic.